Throughout history, the design of a good chair that is comfortable for large numbers of people has remained one of the most persistent furniture design problems. This difficulty stems from the fact that people differ significantly in size, shape, and proportion. Individuals of the same height may differ in leg length or back length by several inches, rendering a chair designed for one person totally unsuitable for the other. It is physically impossible to accommodate the whole range of human sizes and proportions in any single design. Prior to the industrial revolution, chairs were custom made one at a time, and if one deviated from the standard size and norm of the mass of individuals, a chair could be easily obtained merely by altering the measurements given to the cabinet maker before the chair was produced. With the onset of the industrial revolution, and the mass production of furniture, the problems of obtaining a good fit in a chair have been substantially compounded. Any design suitable for mass production must necessarily involve compromises to accommodate the largest number of people and therefore the largest possible marketplace. While this process can produce excellent seating, the resulting chairs are only truly comfortable for those who are statistically average in size and proportion.
The problems associated with different sizes and proportions of people can be overcome to some extent by allowing for adjustable sections in the chair. Such chairs are normally found today in dentists' offices, and in prior times were commonly found the barber's shop. In both places, people were obliged to sit for fifteen minutes to an hour at a time without unnecessary movement. Consequently, dentists and barbers sought the most comfortable and adjustable chair possible. These chairs are extremely expensive, prone to wear, and somewhat unattractive for home use. Further, individual seating in a home does not normally involve adjusting a chair for each person who sits in the chair. Man, being a territorial animal, normally gravitates to a certain chair or seating position for any given room. Consequently, a custom chair is the only practical way to provide true comfort and proper support for an individual in a home or office setting.
Customarily, the manufacture of individual, specific sized pieces of furniture is extremely expensive. This is because the jigs, tools, and assembly procedures used to manufacture a standardized chair cannot be broken down quickly and easily to accommodate the wide variety of measurements necessary to customize a chair to an individual. Specifically, in order for a chair to be truly comfortable for an individual, the following variable measurements must be taken into account: (a) the height of the seat above the floor, (b) the length of the seat, (c) the tilt of the seat, (d) the position of the lumbar support, (e) the length of the thoracic support, (f) the tilt of the thoracic support, (g) the position of the cervical support, (h) the length of the arm rest, and (i) the height of the arm rest. While a mass produced chair could probably be produced under conventional techniques with one or two variations in measurements, it has been heretofore virtually impossible to provide for variations of all of the foregoing measurements in a mass produced chair.
Indeed, it is difficult even to obtain the measurements for an individual so that a chair can be produced for that individual. U.S. Pat. No. 3,112,137 which issued to J. B. Drenth on Nov. 26, 1963 discloses a jig for making custom chairs. This jig showed some, but not all, of the adjustments necessary to produce a custom chair. Further, it appears that this jig was used in the production of unique one-of-a-kind chairs, and not in the production of mass produced chairs as is applicant's invention.